Rivera, operating on his own account, had undertaken a campaign against the western Rio Grande, but so bitter was factional feeling that his rival, Lavalleja, sent a force to pursue and fight him, while the new Buenos Aires government was induced to sign a treaty of peace largely because Rivera's success against the Brazilians might make him strong enough to be dangerous. Both Brazil and Argentina were tired of the tedious, expensive war, and both governments had preoccupations within their own territories. Through the intervention of the British Minister the terms were agreed upon. Brazil and Argentina both gave up their claims to Uruguay, the region was erected into an independent republic, and Brazil and Argentina pledged themselves to guarantee its independence during five years. At that time Argentina was convulsed by the struggle between the federalists and the unitarians, and the Uruguayans were also divided into two camps--the followers of Lavalleja and those of Rivera. Neither in Argentina nor in Uruguay were these divisions parties in any proper sense of that term. They were military factions, whose ambitious leaders seem to have been always willing to sacrifice the interests of the country at large to secure a partisan advantage. The Argentine troops who returned home from the war against Brazil promptly plunged their country into the bloodiest civil war known in her history, and Uruguay did not delay in following the example. The first chief magistrate of independent Uruguay was Jose Rondeau, an Uruguayan who had become one of the greatest Argentine generals. However, Lavalleja and Rivera were the real factors in the situation, and Rondeau's efforts to conciliate both at the same time failed. The Constituent Assembly, which soon met and framed a paper constitution, was controlled by Lavalleja's partisans. Rondeau was deposed and Lavalleja assumed the reins of power. Rivera prepared to march on Montevideo and dispute the matter by arms, but the representatives of Argentina and Brazil intervened and a compromise was effected. Rivera got the best of the bargain, being given command of the army, and after the constitution had been declared (July 18, 1830), he became, as a matter of course, the first president of Uruguay. CHAPTER V CIVIL WAR AND ARGENTINE INTERVENTION Except for an expedition against the remnants of the once formidable Charrua Indians, the first two years of independence passed in peace. Since the expulsion of Artigas, the country had prospered and its population had risen nearly threefold within twenty-five years, in spite of the bloody fighting which occurred from 1811 to 1817 and from 1825 to 1828. The settlements had spread far back from the coast, and many of the principal interior towns date from this period.